Promoter analysis of the avirulence gene Avr9 of the fungal tomato pathogen Cladosporium fulvum in the model filamentous fungus Aspergillus nidulans

2003 ◽  
Vol 43 (2) ◽  
pp. 96-102 ◽  
Author(s):  
Sandor S. Snoeijers ◽  
Alejandro Pérez-García ◽  
Theo Goosen ◽  
Pierre J. G. M. De Wit
Keyword(s):  
Aspergillus Nidulans ◽  
Filamentous Fungus ◽  
Promoter Analysis ◽  
Avirulence Gene ◽  
Cladosporium Fulvum ◽  
Tomato Pathogen

Nitrogen limitation induces expression of the avirulence gene avr9 in the tomato pathogen Cladosporium fulvum

1994 ◽  
Vol 243 (3) ◽  
pp. 277-285 ◽  
Author(s):  
G. F. J. M. Van den Ackerveken ◽  
R. M. Dunn ◽  
A. J. Cozijnsen ◽  
J. P. M. J. Vossen ◽  
H. W. J. Van den Broek ◽  
...  
Keyword(s):  
Nitrogen Limitation ◽  
Avirulence Gene ◽  
Cladosporium Fulvum ◽  
Tomato Pathogen

scholarly journals Additional Resistance Gene(s) Against Cladosporium fulvum Present on the Cf-9 Introgression Segment Are Associated with Strong PR Protein Accumulation

1998 ◽  
Vol 11 (4) ◽  
pp. 301-308 ◽  
Author(s):  
Richard Laugé ◽  
Alexander P. Dmitriev ◽  
Matthieu H. A. J. Joosten ◽  
Pierre J. G. M. De Wit
Keyword(s):  
Resistance Gene ◽  
Avirulence Gene ◽  
Fungal Mycelium ◽  
Protein Accumulation ◽  
Cladosporium Fulvum ◽  
Leaf Chlorosis ◽  
Tomato Pathogen ◽  
Or Genes ◽  
Introgression Segment ◽  
Weak Resistance

The existence of a gene or genes conferring weak resistance against the fungal tomato pathogen Cladosporium fulvum, in addition to the Cf-9 resistance gene, present on the Lycopersicon pimpinellifolium Cf-9 segment introgressed into L. esculentum, was demonstrated with strains of C. fulvum lacking a functional Avr9 avirulence gene and tomato genotypes lacking a functional Cf-9 gene, respectively. Two mutant strains, obtained by disruption of Avr9 in race 4 and race 5 of C. fulvum, do not trigger the hypersensitive response-mediated resistance on MM-Cf9 genotypes that is normally induced after recognition of the AVR9 elicitor. However, when these strains are inoculated onto MM-Cf0 and MM-Cf9 genotypes, adult MM-Cf9 plants still show weak resistance. This resistance is not related to the Cf-9 gene, as ethyl methanesulfonate (EMS)-generated Cf-9 mutants retained weak resistance. Growth of the fungus in the leaf mesophyll is strongly inhibited, whereas re-emergence of fungal mycelium and conidiation are poor. Strong accumulation of pathogenesis-related proteins and early leaf chlorosis are associated with this phenotype of weak resistance. A search among natural strains lacking the Avr9 gene revealed that one strain is able to overcome this weak resistance. Possible mechanisms underlying this weak resistance are discussed. The presence of the additional weak resistance gene(s) could explain why the resistance of Cf9 genotypes has not been overcome so far in practice.

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